(a) Field of the Invention
The present invention relates to an engine control system and a method thereof. More particularly, the present invention relates to an engine control system and method that operate an engine using temperatures of exhaust gas detected by two temperature sensors disposed within an exhaust manifold.
(b) Description of the Related Art
In general, an engine provides driving torque through combustion of a fuel injected into a plurality of combustion chambers. Exhaust gas from the combustion chamber of the engine is exhausted to a turbocharger or an exhaust gas recirculation device through the exhaust manifold. Flow energy of the exhaust gas supplied to the turbocharger rotates a turbine of the turbocharger, and rotates a blower connected to the turbine via a rotating shaft to supply the flow energy of the exhaust gas to a cylinder of the engine by suctioning and pressurizing air from the exterior.
Accordingly, when air having higher pressure than atmospheric pressure is excessively supplied to the engine, a substantial amount of air may be supplied to an engine having the same exhaust amount. Further, when increasing an injection amount of a fuel, output of the engine may be increased. Moreover, the exhaust gas exhausted from the combustion chamber via the exhaust manifold is reintroduced into the combustion chamber of the engine using an exhaust gas recirculation (EGR) device. In general, when a ratio of air in a mixture is substantially high to be combusted, mono-nitrogen oxide (NOx) is increased. Accordingly, the EGR device is a system which remixes some (e.g., about 5 to 20%) of the exhaust gas exhausted from the engine in the mixture to reduce an amount of oxygen within the mixer and to suppress generation of the NOx by preventing combustion.
In particular, an amount of air excessively supplied to a combustion chamber via the turbocharger and an amount of exhaust gas recirculated through the EGR device may be operated based on a temperature of the exhaust manifold. However, the exhaust gas of the combustion chamber exhausted through the exhaust manifold may cause difficultly in the operation of the turbocharger and the EGR device due to a difference in an amount of fuel injected into each combustion chamber, a difference of intake air to be introduced into each combustion chamber, a temperature difference within the exhaust manifold, and the like.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.